1. Field of the Invention
The present invention is in a pneumatic conveyor for transporting powder by using air especially high-pressure air.
2. Description of the Prior Art
A batch plug conveyor is known as a high-pressure pneumatic conveyor and typically needs a large pressure tank adapted to charge powder. In a typical, exemplary configuration, a conveyor has at least upper and lower tanks connected in series. Discharge valves connected to these tanks are operated in order that powder charged in the upper tank is supplied to the lower tank and the powder within the lower tank is pressurized so as to be transported successively. In an apparatus having such pressure tanks, valves such as butterfly valves and/or ball valves are used, thus complicating the operation. The valves are used for actuation in ambient powder and so tend to be worn away be the powder, causing leakage of air. In addition, apparatus equipped with large pressure tanks have increased height and disadvantageously require a large installation space together with increased cost.